The present invention relates to a ratchet tool that has a toothed engaging ring rotatably received in the head of the tool and an adjacent angle 2-4 degrees is defined from a center of the engaging ring to any two adjacent teeth on the engaging ring.
A conventional ratchet tool is shown in FIGS. 1 and 2 and generally includes a head 10 with a hole 11 for receiving an engaging ring 20 therein and fastening clamps 13 are used to retain the engaging ring 20 in the hole 11. A side hole 12 is defined in a side of the head 10 and communicates with the hole 11. A pawl 21 is movably received in the side hole 12 and biased by a spring 22. An end cap 23 seals the side hole 12 such that the pawl 21 and the spring 22 are retained in the side hole 12. The pawl 21 has teeth 211 which are matched with the teeth 201 on an outer periphery of the engaging ring 20. An inherent problem is that, as shown in FIG. 3, the torque output is small if the number of the matched teeth 211 and 201 is less than a certain amount of number. Gaps between the teeth 211, 201 will be too large. As shown in FIG. 4, a larger number of the matched teeth 211 and 201 requires much precise machining processes and the teeth 211, 201 could slide over each other because of the short height of the teeth 211, 201.
The present invention intends to provide reinforcement teeth structure for the engaging ring and the pawl so as to increase the torque that the ratchet tool can output.
In accordance with one aspect of the present invention, there is provided a ratchet tool that includes a head with a hole in which an engaging ring is received, and a side hole is defined from a side of the head so as to receive a pawl biased by a spring therein.
The engaging ring has first teeth defined in an outer periphery thereof and which are engaged with second teeth defined in a side of the pawl. An adjust angle xe2x80x9caxe2x80x9d of 2 to 4 degrees is defined between a center of the engaging ring and two points of two adjacent first teeth of the engaging ring. An angle xe2x80x9cbxe2x80x9d between two adjacent face of two adjacent second teeth is larger than an angle xe2x80x9ccxe2x80x9d between two faces of any first tooth. A height xe2x80x9cDxe2x80x9d of any of the first teeth is not less than a height xe2x80x9cdxe2x80x9d of any of the second teeth.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.